Reality:In the study, children whose parents described them as “extraordinarily cheerful and optimistic,” “never sees the dark side” or “never worries” were less likely to live to an old age. This is one of “the biggest bombshells of the project,” the researchers write.

“We keep hearing this advice to cheer up and stay happy because it will keep you healthy,” Friedman says. “We just disagree with that after seeing the results of the study.”

The participants who lived long, happy lives “were not cynical rebels and loners” but accomplished people who were satisfied with their lives. Many knew that worrying is sometimes a good thing. The authors also looked at a study of Medicare patients that found that “neuroticism was health-protective.”

People think this mostly because excessive stress is known to be extremely unhealthy. But moderate amounts of (reasonable) worry my have benefits that outweigh the health cost, or as far as I know, it could even be unhealthy to have too-low stress as well.

Myth No. 2. Gardening and walking aren’t enough to keep you healthy.

The authors say the government’s guidelines that recommend spending 30 minutes at least four times a week expending energy at a moderate to intense level is “good up-to-date medical advice but poor practical advice.”

Reality:Being active in middle age was most important to health and longevity in the study. But rather than vow to do something to get in shape (like jogging) and then hate it and not stick with it, find something you like to do.

“We looked at those who stayed active,” Friedman says. “It wasn’t the kids on sports teams. It’s the ones who had activities at one point and had the pattern of keeping them … They were doing stuff that got them out of the chair … whether it was gardening, walking the dog or going to museums.”

I think they mean that a consistent habit of a little physical activity is sufficient for most of the benefits, and that a short-lived enthusiasm for ultra-marathons won’t count for as much as the same work spread out over a larger time.

Myth No. 3. Lighten up; being serious is bad for you.

Reality:One of the best childhood personality predictors of longevity was conscientiousness — “qualities of a prudent, persistent, well-organized person, like a scientist or professor — somewhat obsessive and not at all carefree,” the authors conclude. They say the most obvious reason “is that conscientious people do more things to protect their health and engage in fewer activities that are risky.”

“What characterized the people who thrived is a combination of their own persistence and dependability and the help of other people,” Friedman says. The young adults who were thrifty, persistent, detail-oriented and responsible lived the longest.

I agree with the obvious reason. You should be fun (it’s attractive and satisfying), but also avoid real danger.

Myth No. 4. Take it easy and don’t work so hard. You’ll live longer.

Reality:Those with the most career success were the least likely to die young. Those who moved from job to job without a clear progression were less likely to have long lives than those with increasing responsibilities.

Among participants who were still working in their 70s, the “continually productive men and women lived much longer than the laid-back comrades. … This production orientation mattered more than their social relationships or their sense of happiness or well-being.”

“It wasn’t the happiest or the most relaxed older participants who lived the longest,” the authors write. “It was those who were most engaged in pursuing their goals.”

I think it’s by now accepted folk wisdom that people who feel like they have nothing to live for, don’t live long. The dog in Where the Red Fern Grows who lays down and refuses to eat after her brother dies, etc.

Myth No. 5. Get married and you will live longer.

Reality:The authors looked at the remarried, steadily married (never divorced), divorced and steadily single and found many differences among the groups and between genders.

“We’re able to say that a sexually satisfying and happy marriage is a very good indicator of future health and long life,” but being single for a woman can be just as healthy as being in a marriage, especially if she has other fulfilling social relationships.

The married men in the study lived the longest. Single men outlived remarried men but didn’t live as long as married men. Among women, the number who divorced their husbands and stayed single lived nearly as long as steadily married women.

“Being divorced was much less harmful to a women’s health,” the authors say.

Women live longer and function better at extreme age. So typically the old man is benefiting from the care of his more competent wife. If she leaves him, he’s definitely worse off. I think it’s as simple as that. But it’s also my experience that men stay hurt for longer when a romantic relationship ends.

By the way, intelligence is correlated with health, for at least the reason that most things that damage your health also damage your intelligence. (Intelligence is the sum of very many small things, genetic and expressed, functioning properly).